"The decentralized market of ideas will address the "quacks" in the room" This used to be the case, it no longer is in the time of social media. The voices of the quacks are amplified and they gain legions of followers. Just look at the rise of Q as an example and the current political climate. Any crazy fact can be thrown out and if it supports their world view, a good percentage of people will believe it without looking any deeper than what the guy on Twitter said.
>>wonder+(OP)
This was never the case unless you have a very strange reading of history. Look how long bad ideas like witches causing problems persisted and the popularity of mob justice for such acts.